Measuring fuel consumption

ABSTRACT

Apparatus and methods are described for measuring fuel consumption of an engine accelerating at constant load. The arrangements disclosed provide for detecting a plurality of predetermined engine rpm speeds and for generating a condition when each of said speeds is reached. In response to these conditions, the arrangements register and store an indication of the quantity of fuel per unit time being consumed at each of the plurality of speeds. The arrangements are controlled so that the measurements are sequentially made during acceleration of the engine, and so that the measurements can be selectably read out at a later time.

United States Patent [21] Appl. No.: 190,838

[52] US. Cl. 73/113, 235/150.21 [51] Int. Cl. Glm /00 [58] FieldofSearch.. 73/113, 114, 115, 116, 117.2,

Holben Feb. 26, 1974 I MEASURING FUEL CONSUMPTION PrimaryExaminer-Richard C. Queisser Assistant Examiner-Ste hen A. Kreitman 7511:12 F.H1beHddfld, P 1 men or o a on Is Attorney, Agent, or FirmJohn T.O'Halloran; Me-

notti J. Lombardi, Jr. [73] Assignee: Conoflow Corporation, Blenheim,

J [57] ABSTRACT [22] Filed: Oct. 20, 1971 Apparatus and methods aredescribed for measuring fuel consumption of an engine accelerating atconstant load. The arrangements disclosed provide for detecting aplurality of predetermined engine rpm speeds and for generating acondition when each of said speeds is reached. in response to theseconditions, the arrangements register and store an indication of thequantity of fuel per unit time being consumed at each of the pluralityof speeds. The arrangements are con- [56] References Cited trolled sothat the measurements are sequentially UNITED STATES PATENTS made duringacceleration of the engine, and so that 3,722,265 3/1973 M612 6! al 73/117.3 the measurements can be selectably read out at a later 3,006,14410/1961 Arnett a a1. 73 113 x rim, 3,677,075 7/1972 Scott 73/1 17.3

9 Claims, 5 Drawing Figures F 5 r 29/ 102.41? I m ur a 7 i PRECLEAR 2o 636 1 I i 11 aw: i CLEARS UPDATE i BASE c q com/r54, sr R lPO/A/TCOUNTER, 1 5 All/0 STORAGE REG/S Tens START L...... l as ,INPUT a, o 1 a3 2 5 6 {I4 FREQUENCY f f i f 5 ,2, 1111 11 1 f lull/Rk 21a Cal/N768):(COUNTER 9 STORAGE EC/STERS TACH 5 -29 R (5) H 1 wear 1 2 a 4 5 84PULSES 28 SELECTOR It) a SWITCH a e/m5 COUNTER OSCILLATO 1 II READOUT a;I /'9 860 T0 056. I ozcoozxa V 6 SYSTEM smp 35 1 PATENIED 82 61974 FULRATE.

FUEL RATf sum 1 or 4 'l ig..1

T/ME FOR FUEL RATE MEASURA'ME'NT VERAQE FUEL RA 1: SELEC r50 Rpm ao'oo Rga e- T/M FOR FUEZ RAT' M'A SURE/VENT AVERA GE 50a RAT 554 5c 7'50 R PM500 10 00 15'00 'eo'oo as'oo so'oo RPM INVENTOR EUGENE F. HOLBENATTORNEY PAIENTEDFEB26I974 3.793.882 Y sags/vs F2 HOL8N ATTORNEYMEASURING FUEL CONSUMPTION CROSS REFERENCE TO RELATED APPLICATION Thisapplication is related to application Ser. No. 124,098, filed Mar. 15,1971, now US. Pat. No. 3722265, and entitled Engine PerformanceComputing Arrangement. The assignee of this cross referenced applicationis the same as that of the instant applica tion.

BACKGROUND OF THE INVENTION This invention relates to apparatus andmethods for measuring fuel consumption, and in particular, to improvedapparatus and methods for determining fuel rate measurements of anengine at one or more selectable engine speeds when the engine isaccelerating at a constant load condition.

According to the arrangement in the cross reference application, acomputing arrangement was described in which the fuel horsepower of anengine under test was calculated and displayed. A programmable networkgenerated a pulse output when a preselected rpm was reached by theengine under test. A control means in response to the output pulsepermitted time clocking pulses to be applied to a register to sense thetime required for a predetermined number of fuel input pulses to begenerated. A fuel consumption meter counting means was coupled to sensethe predetermined number of fuel input pulses to be generated. A fuelconsumption meter counting means was coupled to sense the predeterminednumber of fuel input pulses, and storage means stored the total timerequired to sense the fuel pulses. A programmed calculating arrangementwas coupled to the storage means and programmed for computing the fuelhorsepower of the engine, and the results of the calculation weredisplayed in a digital readout. Insofar as the cross referenceapplication is required for a full understanding and to enable one topractice this invention, it is incorporated by reference herein.

The cross referenced application, in essence, was concerned with themeasurement of fuel rate wherein it measured the time required for agiven volume of fuel to pass through the engine. Accordingly, aconsiderable amount of novel circuitry and counting techniques wererequired in order to arrive at the final solution, that being thecalculation of engine performance. The proposed methods and embodimentsaccording to the instant invention have been developed to make a fuelmeasurement directly, so that the calculation of final engineperformance can be made easier. In a first embodiment, the fuel ratemeasurement is at an instant at which the selected rpm is reached whichmeans that the measurement of the fuel rate will occur slightly afterthe selected rpm. In the second embodiment, the measurement of fuel rateis done continuously, and at the instant the selected rpm is reached aparticular registration of fuel consumption is stored.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide apparatus and methods for measuring fuel consumption of anengine accelerating at constant load.

Another object of this invention is to provide apparatus and methods ofmeasuring fuel consumption of an engine at one or more selectable enginespeeds when the engine is accelerating at a constant load condition.

According to the broader aspects of the invention there is provided ameans for measuring fuel rate of an engine including means forselectably detecting a plurality of rpm conditions, means forsequentially registering and storing a measurement of fuel per unit timebeing consumed at each of the conditions, and means to cause themeasurements in response to each rpm condition being reached by saidengine.

According to a feature of the invention, the apparatus for measuringfuel consumption of an engine accelerating at constant load comprises afirst means for detecting a plurality of predetermined engine rpmspeeds, a second means for generating a pulse when each of said speedsis reached, a third means responsive to said pulse for registering andstoring an indication of the quantity of fuel per unit time beingconsumed at each of said plurality of speeds, and fourth meansresponsive to said third means to control said first means, whereby saidfirst means sequentially indicates said plurality of predeterminedspeeds.

According to a method for measuring fuel consumption of an engine at oneor more selectable engine speeds when the engine is accelerating at aconstant load condition, the method comprises the steps of detecting afirst rpm of a plurality of predetermined rpm speeds, initiating a timebase at each detected speed, counting fuel consumption fuel pulses forthe detected speed for a period determined by the time base, storing theregistered count, and updating the detection to another of the pluralityof speeds after storage of the registered count for the first detectedspeed.

According to another method for measuring fuel consumption of an engineat one or more selectable engine speeds when the engine is acceleratingat a constant load condition, the method comprises the steps ofactivating a free running time base, continuously measuring the fuelrate and updating the measurement in a counting register, clearing theregister in a fixed interval of time determined by the time base,detecting a first rpm of a plurality of engine rpm speeds, transferringto a storage register the continuous current rate at the instant thefirst rpm is detected, and updating the detection to a second rpm andenabling the continuous counting.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects andfeatures of the invention will be more fully understood and appreciatedupon consideration of the following detailed description of apparatusorganized in accordance therewith, the description being intended to beread in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates the curve for fuel rate versus rpm useful inunderstanding the operation of the apparatus for a first embodiment;

FIG. 2 is a block diagram of the apparatus for the measuring of fuelconsumption of an engine at one or more selectable engine speedsaccording to the first embodiment;

FIG. 3 is a curve useful in understanding the invention according to asecond embodiment;

FIG. 4 is a block diagram of the apparatus for measuring fuelconsumption of an engine at one or more selectable speeds for the secondembodiment; and

FIG. 5 illustrates a circuit for use with a DC tachometer which may beused with either one of the embodiments described in connection withFIGS. 2 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1 and 2,a method and apparatus for measuring fuel consumption of an engine atone or more selectable engine speeds is illustrated. For instance, asshown in FIG 1, if an engine is permitted to accelerate at a constantload condition, represented by the curve of fuel rate vs. rpm, it isdesirable to measure the rate of fuel consumption at various rpms of theengine. It is recognized that as the engine increases in rpm at somerate of increase, the measurement of the fuel rate must be made quickly.The system of FIG. 2 begins the measurement of fuel rate at the instantthe selectable rpm is reached. FIG. 1 shows that at the selectable rpm,for example, 500 rpm, the time for fuel rate measurement is started andthe average fuel flow rate occurs slightly after the selected rpm isreached.

The apparatus for implementing this arrangement is illustrated in FIG.2. The arrangement includes an input AND gate 1 which has an enginetachometer input and a start pulse input. The output 21 from AND gate 1triggers a frequency divider 2 whose output 22 is coupled to set pointcounters 3 and 4. The output of the set point counters on lines 23 iscoupled to AND gate 5, whose output on line 24 triggers time base 6. TheQ point of time base 6 is coupled by line 25 to AND gate 7 which alsohasa digital input from a fuel meter. Such a positive displacement meterwhich is ca pable of being used with this invention is disclosed incopending application of T. R. Metz (3), Ser. No. 180,958, filed Sept.16, 1971 and assigned to assignee of this application. The output fromAND gate 7 is coupled by line 26 to trigger the counting register 8.Line 25 also is coupled to the differentiators C and R which clear thecounting register 8 to begin the count of fuel pulses. Output lines 27from the counting register 8 are coupled to five storage registers 9.Oscillator is coupled by lines 28 to clear the set point counters at apredetermingd rate. Update counter 11 which is triggered by the Q oftime base 6 from line 29 is coupled by lines 30 to the frequency divider2 and by lines 31 to the BCD to decimal decoder 12. The outputs 32 ofthe decoder 12 are coupled E) five NOR gates 13-17 which also haveinputs from Q of the time base. The outputs 33 from the NOR gates 13-17are coupled to the five storage registers 9. The output line 34 from thestorage register is coupled to a selector switch 18 whose output isterminated on readout 19 where the fuel rate at the various rpmconditions may be indicated. One output point (6) of the decoder 12 iscoupled by line 35 to the input of AND gate 1 to serve as a system stop.A preclear 20 clears the update counter, the set point counters, and thestorage registers so that another series of readings may be taken andindicated on readout 19.

The operation of the system according to FIG. 2 may be summarized asfollows. The engine rpm is measured by a digital tachometer whose outputis a certain number of pulses per second directly related to revolutionsper minute of the engine. For instance, the tachometer has 30 pulses perrevolution of the engine so that at 500 rpm, the rate of pulses is15,000 pulses/minute or 250 pulses/second. If the period of oscillator10 is set at 0.2 seconds, then in 0.2 seconds, 50 pulses will be countedby the set point counters 3 and 4 if the frequency divider 2 was set toa divide by one. With the frequency divider 2 set to divide by one, theengine is started from 0 rpm and is accelerated. Each 0.2 seconds,counters 3 and 4 count the pulses until 50 or more is reached. Thiscount is equivalent to 500 rpm of the engine under test. At thisinstant, the BCD output on lines 23 which is the equivalent of decimal50 activates AND gate 5 to initiate the time base 6. The Q po int oftime base 6 is initiated, or goes to a 1 state,

and Q goes to 0. When Q goes to the 1 state, the differentiators R and Cclear the counting register 8 to zero, to begin the count of fuel inputpulses which are now permitted to reach the counting register 8 fromenabled AND gate 7. The period of time base 6 is set, as described inthe cross referenced application, so that the pulses reaching countingregister 8 are equivalent to gallons/minute, gallons/hour, orpounds/hour, etc. In the initial state, update counter 11 was set togive a BCD output equivalent to one, or divide by one, which in turnsets the BCD to decimal decoder 12, so that all its outputs on line 32were in a l state except output No. 1 which is in 0 state. When Q was inan initial 1 state, all the outputs on lines 33 of NOR gates 13 through17 were in the 0 state sg that each of 5 storage registers 9 wereclosed. When Q went to the 0 state, when 500 rpm was reached, the outputof NOR gate 13 goes to the 1 state so that the No. 1 storage register ofregisters 9 was opened to receive the co i mt from the, countingregister 8. At the same time that Q went to the 0 state, it inhibitedthe input AND gate 1 by line 29 so that no more pulses from thetachometer could be receiveg to interfere with the counting of fuelpulses. The Q pulse is also present at the toggle position of the updateco unter 11 but does not change the BCD output until Q goes back to the1 state.

After the time base 6 has completed its measurement of time (which isset by the units of fuel rate), the Q point re turns to 0 state and Qreturns to the 1 state. When Q returns to the 1 state, it toggles theupdate counter 11 to the divide by 2 condition. This action gives a BCDnumber of, for example, 010 which changes the decoder 12 to closechannel No. 1 argi prepare channel No. 2 to be initiated the next time Qgoes to the 0 state. At the same time Q returned to the 1 state, itopened AND gate 1 to again permit tachometer pulses to be received. Nowas the tachometer pulses are received, they are divided by two so thatevery other pulse is sent to the set point counters 3 and 4. When thecount reached 50 or more in the counters, which is now equivalent to1,000 rpm, the sequence of events occurs again to record and store thefuel rate at 1,000 rpm. This procedure repeats for each 500 rpmincrements until the decoder 12 reaches channel 6 which goes to the 0state and inhibits AND gate 1 which stops all further recording oftachometer input pulses. No further initiation can occur until thepreclear 20 is initiated.

At this point, the test would be terminated and selector switch 18 wouldbe set to sequentially read out on the readout 19 the fuel rate at thevarious rpm conditions.

Referring now to FIGS. 3 and 4, another embodiment according to theinvention is described for measuring fuel consumption of an engine atone or more selectable engine speeds. For example, as illustrated inFIG.

3, if an engine is permitted to accelerate at a constant load conditionit is desirable to measure the rate of fuel consumption at the variousrpms of the engine to provide a fuel rate vs. rpm curve as illustrated.It is recognized that as the engine increases in rpm, at some rate ofincrease, the measurement of fuel rate must be made rapidly and at atime which can be averaged so that it can be considered to berepresentative of the exact rate at the exact rpm. This embodimentcontinuously measures fuel rate and stores the continuously updated ratein a counting register. This continuously current rate is transferred toa storage register at the instant the selected rpm is reached. Theaverage fuel flow rate can now occur either slightly before the selectedrpm, slightly after the selected rpm or at the exact selected rpm. Theapparatus for an implementation of this embodiment is illustrated inconnection with FIG. 4.

An input AND gate 41 includes a start input and a tachometer input. Thegate 41 output by line 67 is coupled through to frequency divider 42which in turn is coupled by line 68 to set point counters 43 and 44. Theoutput from set point counters 43 and 44 is coupled by lines 69 to NANDgate 45. A time base 46 has its Q point coupled by line 70 to the clearpoint of the set point counters and to the counting register clear 48. Acapacitor C is tied to ground at this point. Q of the time base 46 isconnected by line 71 to the input AND gate 41 and AND gate 47 which alsohas an input from the fuel meter. The fuel meter may be of the type asindicated in the T. R. Metz (3) copending application. AND gate 47output on line 72 is coupled to the counting register 48 whose outputson lines 73 are coupled to the five storage registers 49. OR gate 50toggles by line 74 update counter 51 whose BCD outputs on line 75 arecoupled to the frequency divider 42 and by lines 76 the BCD to decimaldecoder 52. Output channels 1-5 of decoder 52 are coupled by lines 77 toNOR gates 53-57. NOR gages 53-57 also have inputs from line 78 connectedto Q of flip-flop 60 which is toggled from NAND gate 45 by line 79 andcleared by line 80 from the Q point of time base 46. Line 81 couples theQ point of time base 46 to the NOR gates inputs 53-57. The outputs online 82 of NOR gates 53-57 are coupled to sequentially enable the fivestorage registers 49, and by lines 83 are coupled to the five inverters61-65 and through to OR gate 50. The outputs from storage registers 49are coupled by line 84 to selector switch 58 whose output is coupled toreadout 59. The system is stopped by channel 6 of decoder 52 which isconnected by line 85 to input AND gate 41. A preclear 66 clears theupdate counter, the set point counters, and the storage registers.

The functional operation of the described system may be summarized asfollows. The engine rpm is measured by a digital tachometer whose outputis a certain number of pulses per second directly related to revolutionsper minute. For instance, the tachometer has 30 pulses per revolution ofthe engine so that at 500 rpm the rate of pulses is 15,000 pulses/minuteor 250 pulses/second. If the period of time base 46 is set to 0.2seconds, then in 0.2 seconds, 50 pulses would be counted by the setpoint counters 43 and 44 if the frequency divider 42 was set to divideby one. With the frequency divider 42 set to divide by one, the engineis started from 0 rpm and is accelerated. Each 0.2 seconds, the counters43 and 44 count the pulses until 50 or more is reached. At thisinstance, the BCD output of the decimal 50 activates the NAND gate 5which is connected to the toggle flip-flop 60.

At the same time that the tachometer pulses are being continuouslycounted, a free running time base 46 has been activating AND gate 47 tocontinuously measure fuel input pulses from the fuel meter. The timebase 46 is designed to give a short period clear pulse at a fixedinterval of time, every 0.2 seconds in this example. The Q terminalcoupled by line clears the counting register 8 cyclically every 0.2seconds so that the number of pulses in the counting register 8 isalways the latest fuel rate counted. When Q is at one state fuel pulsesare counting. If, during the cycled counting of fuel pulses, the setpoint counters 43 and 44 reach 50, NAND gate 45 is enabled, the Q offlipflop 26 goes to 0 state which opens NOR gate 53. This was previouslyset by the condition of decoder 52, since update counter 51 is also in adivide by one condition. The No. 1 storage register 9 now reads thecurrent count of fuel rate pulses until Q of the time base 46 returns tothe 0 state. At this instant, flip-flop 60 returns to 1 state, lockingthe last fuel numbers in storage position 1, clearing the countingregister to 0, momentarily inhibiting AND gate 41 to prevent furtherreading of tachometer pulses. As soon as any one of the outputs of theNOR gates 53 to 57 opened momentarily to store pulses, the output of ORgate 50 went to a 0 state. When the NOR gates 53-57 returned to theiroriginal conditions, at instant Q of time base 46 went to 0 state tocomplete fuel pulse counting, the output of OR gate 50 returned to a Istate which switched update counter 51 to divide by two and resetdecoder 52 by lines 76 to the channel No. 2 position. This entireprocedure repeats itself continuously until decoder 52 reaches channelNo. 6 position which inhibits by line AND gate 41 and stops all furthertesting until preclear 66 is activated.

At this point, the test would be terminated and selector switch 18activated to sequential read out on the readout 19 the fuel rate at thevarious rpm conditions.

FIG. 3 shows that there would be an under register or over registerlimit of error which would depend upon the point at which the 50 countswas reached in relation to the time base counting of fuel pulses. In anyevent, any reading by this embodiment would be less in error than thefirst embodiment, but it would be variable.

FIG. 5 shows an arrangement which can be incorporated into the describedembodiments wherein the indicated type tachometer input is replaced by aDC type tachometer input. Referring now to FIG. 5, a DC tachometer hasits plus terminal connected across variable resistor R4 and fixedresistor R3. The midpoint of the resistors is connected through contactCC1 of relay RRl to resistor R1 and to the negative terminal ofoperational amplifier 91. The midpoint between resistor R4,R3 is alsoconnected by contact CC2 of relay RR2 to resistor R2 and to the negativeinput of the operational amplifier 91. The output of the operationalamplifier is connected to the fuel time base 92 whose output is used toupdate counter 94 which is coupled to converter 93. One output fromconverter 93 controls transistor T1 which is turned on at 500 rpm andthe other output from converter 93 is coupled to transistor T2 which isactivated at 1,000 rpm.

This circuit permits the use of a DC tachometer with either of theembodiments previously described. In this arrangement, the convertersets either transistor T1 or T2 for a particular selectable rpm. Withthe selected transistor turned on, the associate relay is activated andcontacts to the DC tachometer are closed to couple the voltage throughthe associated dropping resistor and to the operational amplifier. Thedropping resistor is selected so that the turn on voltage level of theoperational amplifier occurs at the selected rpm of the engine. Theoperational amplifier then initiates the fuel time base as previouslydescribed in connection with the two embodiments.

Although we have described above the features of the invention inconnection with a specific example, it should be clearly understood thatthis description is made only by way of example and not as a limitationon the scope of the invention as set forth in the objects and featuresthereof and in the accompanying claims.

I claim:

1. Means for measuring fuel rate of an engine comprising:

first means for selectably detecting a plurality of rpm conditions;

means for generating signals representative of fuel per unit time beingconsumed;

second means for registering and storing the signals representative offuel per unit time being consumed at each of the plurality ofconditions; and

means coupled to said first and second means to cause the registeringand storing in response to each rpm condition being reached by saidengine, whereby the stored signals represent the measured fuel rate ofthe engine.

2. The means of claim 1 including means for selectably indicating eachof said stored signals.

3. Apparatus for measuring fuel consumption of an engine accelerating ata constant load comprising:

first means for detecting a plurality of predetermined engine rpmspeeds;

second means for generating a pulse when each of said speeds is reached;

means for generating signals corresponding to fuel consumption rates;

third means responsive to said pulse for registering and storing thesignals at each of said plurality of speeds; and

fourth means responsive to said third means to control said first means,whereby said first means sequentially detects said plurality ofpredetermined speeds.

4. The apparatus of claim 3 including fifth means responsive to saidfourth means to cause sequential storage of each registered fuelconsumption signal.

5. Apparatus for measuring fuel consumption of an engine at one or moreselectable engine speeds when the engine is accelerating at a constantload condition, comprising:

means for detectinga first rpm of a plurality of predetermined enginerpm speeds;

a time base generating means;

means for generating fuel consumption pulses;

means for initiating said time base means at each detected speed;

means for counting the fuel pulses for said detected speed for a perioddetermined by said time base means;

means for storing the registered count of the fuel pulses; and means forupdating the detection to a second rpm of said plurality after storageof the registered count for said first rpm.

6. Apparatus for measuring fuel consumption of an engine at one or moreselectable engine speeds when the engine is accelerating at a constantload condition comprising:

means for generating a free running time base signal and fuelconsumption rate pulses;

a counting register for continuously registering the fuel consumptionrate pulses and updating the rate in said counting register;

means for clearing the counting register in a fixed interval of timedetermined by said time base signal;

means for detecting a first rpm of a plurality of engine rpm speeds;

a storage register and means coupled for causing transfer to saidstorage register of the fuel consumption rate pulses registered at theinstant the first rpm is detected; and

means for updating the detection to a second rpm of said plurality, andthe fuel consumption rate pulse registering continues in said countingregister for said second rpm, whereby the fuel rate of the engine ismeasured and stored at selected speeds.

7. Apparatus for measuring for said second rpm fuel rate of an engineaccelerating at a constant load comprising:

first means for detecting a plurality of predetermined engine rpmspeeds;

second means for generating a pulse when each of said speeds is reached;

means for generating pulses indicating the quantity of fuel per unittime being consumed by the engine;

third means responsive to said pulse for registering and storing thepulses indicating the quantity of fuel per unit time being consumed ateach of said plurality of speeds;

fourth means responsive to said third means to control said first means,such that said first means sequentially detects said plurality ofpredetermined speeds;

fifth means responsive to said fourth means to cause sequential storageof each registered indicating pulses; and sixth means for selectablyreading out each of stored indicating pulses.

8. A method of measuring fuel consumption of an engine at one or moreselectable engine speeds when the engine is accelerating at a constantload condition, comprising:

detecting a first rpm of a plurality of predetermined engine rpm speeds;

generating a time base signal and fuel consumption pulses at eachdetected speed;

counting the fuel pulses for said detected speed for a period of timedetermined by said time base signal;

storing the registered count of the fuel pulses; and

updating the detection to a second rpm of said plurality after storageof the registered count for said first rpm.

detecting a first rpm of a plurality of engine rpm speeds;

transferring to a storage register the fuel consumption rate pulsesregistered at the instant the first rpm is detected; and

updating the detection to a second rpm of said plurality and enablingthe registering of the fuel consumption rate pulses in said countingregister for said second rpm.

1. Means for measuring fuel rate of an engine comprising: first means for selectably detecting a plurality of rpm conditions; means for generating signals representative of fuel per unit time being consumed; second means for registering and storing the signals representative of fuel per unit time being consumed at each of the plurality of conditions; and means coupled to said first and second means to cause the registering and storing in response to each rpm condition being reached by said engine, whereby the stored signals represent the measured fuel rate of the engine.
 2. The means of claim 1 including means for selectably indicating each of said stored signals.
 3. Apparatus for measuring fuel consumption of an engine accelerating at a constant load comprising: first means for detecting a plurality of predetermined engine rpM speeds; second means for generating a pulse when each of said speeds is reached; means for generating signals corresponding to fuel consumption rates; third means responsive to said pulse for registering and storing the signals at each of said plurality of speeds; and fourth means responsive to said third means to control said first means, whereby said first means sequentially detects said plurality of predetermined speeds.
 4. The apparatus of claim 3 including fifth means responsive to said fourth means to cause sequential storage of each registered fuel consumption signal.
 5. Apparatus for measuring fuel consumption of an engine at one or more selectable engine speeds when the engine is accelerating at a constant load condition, comprising: means for detecting a first rpm of a plurality of predetermined engine rpm speeds; a time base generating means; means for generating fuel consumption pulses; means for initiating said time base means at each detected speed; means for counting the fuel pulses for said detected speed for a period determined by said time base means; means for storing the registered count of the fuel pulses; and means for updating the detection to a second rpm of said plurality after storage of the registered count for said first rpm.
 6. Apparatus for measuring fuel consumption of an engine at one or more selectable engine speeds when the engine is accelerating at a constant load condition comprising: means for generating a free running time base signal and fuel consumption rate pulses; a counting register for continuously registering the fuel consumption rate pulses and updating the rate in said counting register; means for clearing the counting register in a fixed interval of time determined by said time base signal; means for detecting a first rpm of a plurality of engine rpm speeds; a storage register and means coupled for causing transfer to said storage register of the fuel consumption rate pulses registered at the instant the first rpm is detected; and means for updating the detection to a second rpm of said plurality, and the fuel consumption rate pulse registering continues in said counting register for said second rpm, whereby the fuel rate of the engine is measured and stored at selected speeds.
 7. Apparatus for measuring for said second rpm fuel rate of an engine accelerating at a constant load comprising: first means for detecting a plurality of predetermined engine rpm speeds; second means for generating a pulse when each of said speeds is reached; means for generating pulses indicating the quantity of fuel per unit time being consumed by the engine; third means responsive to said pulse for registering and storing the pulses indicating the quantity of fuel per unit time being consumed at each of said plurality of speeds; fourth means responsive to said third means to control said first means, such that said first means sequentially detects said plurality of predetermined speeds; fifth means responsive to said fourth means to cause sequential storage of each registered indicating pulses; and sixth means for selectably reading out each of stored indicating pulses.
 8. A method of measuring fuel consumption of an engine at one or more selectable engine speeds when the engine is accelerating at a constant load condition, comprising: detecting a first rpm of a plurality of predetermined engine rpm speeds; generating a time base signal and fuel consumption pulses at each detected speed; counting the fuel pulses for said detected speed for a period of time determined by said time base signal; storing the registered count of the fuel pulses; and updating the detection to a second rpm of said plurality after storage of the registered count for said first rpm.
 9. A method of measuring fuel consumption of an engine at one or more selectable engine speeds when the engine is accelerating at a constant load coNdition, comprising: generating a free running time base signal and fuel consumption rate pulses; continuously registering the fuel consumption rate pulses and updating the pulses in a counting register; clearing the register in a fixed interval of time determined by said time base signal; detecting a first rpm of a plurality of engine rpm speeds; transferring to a storage register the fuel consumption rate pulses registered at the instant the first rpm is detected; and updating the detection to a second rpm of said plurality and enabling the registering of the fuel consumption rate pulses in said counting register for said second rpm. 